When a woman is going down on a man, right before he ejaculates he pushes down on the back of her head (or punches her in the back of the head) causing he to choke and cough thus shooting the semen out her nose. Like a dragon shooting flames or ice of it's nose.
See, sticky dragon or white dragon

Jenny was sucking my deek off so I punched her in the back of the melon and as she shot my load out her nose I screamed "Ice Dragon!" . . . it was awkward the next day at work.